1. Technical Field
This invention relates generally to releasable attaching devices for constraining deployable elements, and more particularly to an attaching device that releases when it is broken by the force from an expanding material.
2. Discussion
Typically, releasable attaching devices are hollow bolts with a sliding piston disposed therein. The piston is rapidly accelerated within the hollow bolt by explosive pressure such that it impacts another portion of the bolt. This impact creates the necessary force to break the bolt, thereby freeing the object being restrained. One drawback to these types of devices is that piston impact can impart a considerable shock on the entire system when it strikes and shears the bolt. This shock may have an undesirable affect on any electronic components in the immediate locality of the bolt. For example, spacecraft, satellites, and the like generally employ a number of these types of attaching devices to constrain deployable elements during launch, maneuvering and during the later release of such elements. Spacecraft and satellites also generally use electronic components and other devices which may be affected by the above described shock. Therefore, it would be desirable to reduce or eliminate this shock without increasing the size, weight and complexity of the attaching device.
One solution that reduces the shock created by the piston impacting within the bolt is to place a shock absorber near the end of the piston stroke, thereby cushioning the blow of the piston. Although a shock absorber does reduce the shock imparted upon the bolt, the shock absorber itself increases the size and mass of the attaching device. Adding a shock absorber also increases the number of operative parts, thereby increasing the overall cost of the device. Therefore, it is an object of this invention to solve one or more of these problems.